Keep on ignoring those discrepancies. If you had any of the cards in question you'd be welcome to post a stock benchmark in the benchmark thread. As you don't I'm not sure why you're that bothered and arguing for reviews which could have well taken a backhander to massage the results slightly to make them more... Juicy.
Honestly you should see some of the comments on high resolution saying that Nvidia are faster at this resolution buy this 670 over a 7970 etc etc.
It works both ways but it's still enough to make me read over them with glazed eyes ha ha.